GB2298655A

GB2298655A - Cathgode arrangement for a device for sputtering a pair targets

Info

Publication number: GB2298655A
Application number: GB9522513A
Authority: GB
Inventors: Hans Kunz; Andreas Sauer; Manfred Schuhmacher; Dietmar Marquardt; Joachim Szczyrbowski
Original assignee: Leybold AG
Current assignee: Balzers und Leybold Deutschland Holding AG
Priority date: 1995-03-09
Filing date: 1995-11-02
Publication date: 1996-09-11
Anticipated expiration: 2015-11-02
Also published as: GB9522513D0; GB2298655B; DE19508405A1; US5944967A

Description

2298655 Cathode arrangement for a device for sputtering a pair of targets

The invention concerns a cathode arrangement for a device for sputtering a pair of targets, with magnet yokes, with targets with narrow, oblong, plate-like configurations and with permanent magnets disposed between the targets and the magnet yokes and with holding devices to fix the magnet yokes to a part of the vacuum chamber wall.

The object of this invention is to create a double cathode for sputtering highly insulating materials which renders possible a high sputtering rate and a stable process. In particular, cooling of the targets, replacement of the targets and the magnetic field configuration are to be optimised. Finally, it is to be possible for the targets to be replaced with particular speed and lack of complexity.

This object is achieved by a common cover plate or base plate, covering both cathodes, with several side plates, extending longitudinally and in parallel to the base plate, capable of being joined to the latter, a centre plate and end plates, the base plate being fixed to a part of the vacuum chamber wall through electrically insulating holding devices and the base plate, together with the side and end plates, enclosing the cathodes, forming a case which is open at one end, only the surfaces of the two targets which are to be sputtered, on the side of the cathodes which faces away from the base plate, being freely accessible from the vacuum chamber.

Further details and characteristics are disclosed by the claims.

The invention permits of a very great variety of possible embodiments; one of these is depicted in greater detail in the accompanying drawings, wherein:

2 Fig. 1 shows the transverse section through a two-cathode arrangement according to the invention, Fig. 2 shows the longitudinal section through the cathode arrangement according to Fig. 1, Fig. 3 shows the top view of the two-cathode arrangement according to Figures 1 and 2, in partial section, Fig. 4 shows an enlarged transverse section through a cathode, and Fig. 5 shows the transverse section through the cathode arrangement according to Fig. 1, but with cathodes removed from the centre plate.

AS shown by Fig. 1, the two cathodes 3, 4 are fixed to the upper part of the wall 5 of the vacuum chamber 6 by means of screws 7, 8 or 9, 10, the cathodes 3, 4 themselves being each coupled either, through pairs of link plates 11, 12 which form chain links, with bearing blocks 13 and insulators 15, by means of screws 17, 18, or with insulators 16 which are directly connected to the bearing blocks 14 by means of screws 19. The insulators 15, 16, in turn, are screwed to the magnet yokes 22, 23 by means of stay bolts 20, 21 or 24, 25, so that the cathodes 3, 4, together with the side plates 26, 27, 28 enclosing them, the magnet yokes 22, 23, the cooling tubes 29, 30 or 31, 32, the permanent magnets 33, 34 or 35, 36 or 53, 54 or 55, 56, the clamping strips 37, 38 or 39, 40, the head plates 41 or 42, the profile strips 43, 44, 45 or 46, 47, 48 and the targets 49 or 50, with their back plates 51 or 52, hang from the upper part of the wall 5.

3 The targets 49, 50, or their back plates 51, 52, are each pressed against the membrane 57, 58 by means of the clamping strips 37 to 40 due to the fact that their edge"parts 59 to 62 facing towards the substrate encompass the back plates 51, 52 and draw each of these firmly towards the magnet yokes 22, 23, for which purpose the edge parts 63 to 66 facing away from the back plates overlap the head plates 41, 42, each of which is additionally connected to the magnet yokes by means of the screws 67, 68.

In order to fix the targets 49, 50 to the magnet yokes 22, 23, the tightening screws 69, 70, which join the clamping jaws 71, 72 or 73, 74 together, are tightened to such an extent that, on one hand, the head plates 41, 42 bear firmly against the upper edge parts 63 to 66 and, on the other hand, the lower edge parts 59 to 62 bear firmly against the distance strips 75 to 78 and firmly join together all parts encompassed by the clamping strips 37 to 40. Since the bearing blocks 13, 14 are fixed to the magnet yoke 22, 23 by means of the screws 20, 21 or 24, 25, they are held by the upper part of the wall 5 of the vacuum chamber 6. At the same time, the cover plate 79 is also supported on the insulators 81, 82, which in turn are retained by the screws 20, 21 or 24, 25. Due to the fact that there is a gap 83 between the bearing block 13 and the insulator 15, the cathodes 3, 4 can execute a certain movement relative to the suspension shown on the right in Fig. 2, in the horizontal plane (due to the fact that the insulators 15, 16 and the bearing blocks 13, 14 are articulated together through the link plates 11, 12 or the screws 17, 18 and thus act in the manner of a chain link). The cathodes 3, 4 are of a very long construction, each of the two cathodes 3, 4 being fixed to several suspensions (the type A shown on the left in Fig. 2) distributed over the length of each and each fixed to a suspension of the type B on the upper part of the wall 5 (shown on the right in Fig. 2).

4 The dark space screen consists of the base plate 79 which extends over the backs of the two cathodes. There is a centrally disposed plate 28 which simultaneously f orms the side wall screen f or both cathodes 3, 4. Further screens 26, 27 are disposed on the outer side faces of the cathodes 3, 4. All screening plates 26, 27, 28 which are perpendicular to the base plate 79 terminate on the same level as the front face of the claw strips or clamping strips 37 to 40. The single-part or multi-part centre plate 28 is clamped, so as to be positionally stable, by means of screws 94, 94',... and is secured by a form-fit. The screws 94, 941,... are protected from coating in the base plate 79.

The lateral screening plates 26, 27 can be removed by undoing the fastening screws 96, 9C,... The gap 90, 91 around the cathodes 3, 4 is dimensioned e.g. at 3 mm for a sputtering pressure of about 3x10 -3.

The compact construction of the two cathodes 3, 4 means that there is only one process zone on the substrate.

Arcing between the cathodes 3, 4 is prevented by the electrically floating suspension of the frame-type dark space screen 26, 27, 28, 29. The screen fastening is fixed, positionally centered, to the cathode body and prevents contact between the screen and the cathodes. The lateral screening plates 26, 27, 80 can have holes 97, 971.... which enable the targets to be changed without loosening the longitudinal screens.

The described cathode arrangement effects particularly good ignition of the cathodes 3, 4.

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 List of References Cathode n Upper part of wall Vacuum chamber Screw 0 qt 11 Link plate 91 Bearing block tv Insulator of Screw It If Stay bolt cl Magnet yoke n Stay bolt U Side plate 99 Centre plate Cooling tube It 91 11 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 so 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Permanent magnet 19 U we Clamping strip it n ft Head plate to Profile strip ty It el 11 we Target we Back plate U Permanent magne we II 99 Membrane n Edge part n Edge part of If 6 7 66 67, 67' 68 69 70, 70', 71 72 73 74 92' 93' 94' 9s,' 96' 97' a Screw m Tightening screws 11 Clamping jaw 91 11 cl Distance strip 19 11 19 Cover plate, base plate End plate Insulator, holding device 91 Gap 91 Contact ramp of Surface, contact ramp 91 Spring Opening, gap It Recess Lug Screw Screw end Screw Hole 8

Claims

Claims

Cathode arrangement for a device for sputtering a pair of targets (49 or 50), with magnet yokes (22, 23) with targets with narrow, oblong, platelike configurations (49, 50 or 51, 52), with permanent magnets (33, 34, 53, 54 or 35, 36, 55, 56) disposed between the targets and the magnet yokes (22 or 23) and with holding devices (A or B) to fix the cathodes (3 or 4) to a part of the wall (5) of the vacuum chamber (6), characterized by a common cover plate or base plate (79), covering both cathodes (3 or 4), with several side plates (26, 27), extending longitudinally and in parallel to the base plate (79), capable of being connected to the latter, a centre plate (28) and with end plates (80), the base plate (79) being fixed to a part of the wall (5) of the vacuum chamber (6) through electrically insulating holding devices (A, A') and the base plate (79), together with the side and end plates, enclosing the cathodes (3, 4), forming a case which is open at one end, only the surfaces of the two targets which are to be sputtered, on the side of the cathodes (3 or 4) which faces away from the base plate (79), being freely accessible from the vacuum chamber (6).

Cathode arrangement according to Claim 1, characterized in that, in the region of the two adjacent cathodes (3 or 4), the base plate (79) can be fitted with a centre plate (28), screening the two cathodes from each other, whose narrow end facing the base plate (79) has pins or lugs (93, 93.1,...) which engage in corresponding openings or recesses (92, 921....) provided in the base plate (79) and which can be locked by the free ends (95, 951....) of screws (94, 941,...) which are retained by tapped holes in the centre plate (79).

9 3. Cathode arrangement according to Claims 1 and 2, characterized in that the base plate (79) is joined to the side plates (26, 27) with its end side faces and to the end plates (80....) by means of pins, bolts or screws (96, 961,...) which are retained in the side faces of the base plate (79).

Cathode arrangement according to the preceding Claims, characterized in that the base plate (79) has openings through which pass the holding devices (81, 811,... or 82, 821,...) for the magnet yokes (22, 23,...), made from electrically insulating material, which are also fixed to the base plate (79).